1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2*4882a593Smuzhiyun.. c:namespace:: DTV.fe 3*4882a593Smuzhiyun 4*4882a593Smuzhiyun.. _FE_SET_TONE: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun***************** 7*4882a593Smuzhiyunioctl FE_SET_TONE 8*4882a593Smuzhiyun***************** 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunName 11*4882a593Smuzhiyun==== 12*4882a593Smuzhiyun 13*4882a593SmuzhiyunFE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone. 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunSynopsis 16*4882a593Smuzhiyun======== 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun.. c:macro:: FE_SET_TONE 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun``int ioctl(int fd, FE_SET_TONE, enum fe_sec_tone_mode tone)`` 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunArguments 23*4882a593Smuzhiyun========= 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun``fd`` 26*4882a593Smuzhiyun File descriptor returned by :c:func:`open()`. 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun``tone`` 29*4882a593Smuzhiyun an integer enumered value described at :c:type:`fe_sec_tone_mode` 30*4882a593Smuzhiyun 31*4882a593SmuzhiyunDescription 32*4882a593Smuzhiyun=========== 33*4882a593Smuzhiyun 34*4882a593SmuzhiyunThis ioctl is used to set the generation of the continuous 22kHz tone. 35*4882a593SmuzhiyunThis call requires read/write permissions. 36*4882a593Smuzhiyun 37*4882a593SmuzhiyunUsually, satellite antenna subsystems require that the digital TV device 38*4882a593Smuzhiyunto send a 22kHz tone in order to select between high/low band on some 39*4882a593Smuzhiyundual-band LNBf. It is also used to send signals to DiSEqC equipment, but 40*4882a593Smuzhiyunthis is done using the DiSEqC ioctls. 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun.. attention:: If more than one device is connected to the same antenna, 43*4882a593Smuzhiyun setting a tone may interfere on other devices, as they may lose the 44*4882a593Smuzhiyun capability of selecting the band. So, it is recommended that applications 45*4882a593Smuzhiyun would change to SEC_TONE_OFF when the device is not used. 46*4882a593Smuzhiyun 47*4882a593SmuzhiyunReturn Value 48*4882a593Smuzhiyun============ 49*4882a593Smuzhiyun 50*4882a593SmuzhiyunOn success 0 is returned. 51*4882a593Smuzhiyun 52*4882a593SmuzhiyunOn error -1 is returned, and the ``errno`` variable is set 53*4882a593Smuzhiyunappropriately. 54*4882a593Smuzhiyun 55*4882a593SmuzhiyunGeneric error codes are described at the 56*4882a593Smuzhiyun:ref:`Generic Error Codes <gen-errors>` chapter. 57